scholarly journals Hydrogen bond-Driven Self-Assembly between Amidinium Cations and Carboxylate Anions: A Combined Molecular Dynamics, NMR Spectroscopy, and Single Crystal X-ray Diffraction Study

2017 ◽  
Vol 12 (13) ◽  
pp. 1587-1597 ◽  
Author(s):  
Michael Thomas ◽  
Thomas Anglim Lagones ◽  
Martyna Judd ◽  
Mahbod Morshedi ◽  
Megan L. O'Mara ◽  
...  
Synlett ◽  
2020 ◽  
Vol 31 (05) ◽  
pp. 434-438 ◽  
Author(s):  
Maria C. Cringoli ◽  
Ottavia Bellotto ◽  
Rita De Zorzi ◽  
Attilio V. Vargiu ◽  
Silvia Marchesan

Minimalistic peptides composed of d- and l-amino acids are attractive building blocks for functional supramolecular materials, including catalysts. d-Amino acids have long been known to promote turn conformations in peptides, yet unexpected twists continue to emerge on their effects on self-assembly. The combination of single-crystal X-ray diffraction and full-atom molecular dynamics have finally unraveled fine details of how l-d-l-tripeptides visit different conformations in solution and establish key interactions in supramolecular structures.


2014 ◽  
Vol 10 ◽  
pp. 432-441 ◽  
Author(s):  
Rainer Hovorka ◽  
Sophie Hytteballe ◽  
Torsten Piehler ◽  
Georg Meyer-Eppler ◽  
Filip Topić ◽  
...  

Two new 9,9’-spirobifluorene-based bis(4-pyridines) were synthesised in enantiopure and one also in racemic form. These ligands act as concave templates and form metallosupramolecular [(dppp)2M2L2] rhombi with cis-protected [(dppp)Pd]2+ and [(dppp)Pt]2+ ions. The self-assembly process of the racemic ligand preferably occurs in a narcissistic self-recognising manner. Hence, a mixture of all three possible stereoisomers [(dppp)2M2{(R)-L}2](OTf)4, [(dppp)2M2{(S)-L}2](OTf)4, and [(dppp)2M2{(R)-L}{(S)-L}](OTf)4 was obtained in an approximate 1.5:1.5:1 ratio which corresponds to an amplification of the homochiral assemblies by a factor of approximately three as evidenced by NMR spectroscopy and mass spectrometry. The racemic homochiral assemblies could also be characterised by single crystal X-ray diffraction.


2009 ◽  
Vol 87 (1) ◽  
pp. 205-211 ◽  
Author(s):  
Barry A Blight ◽  
James A Wisner ◽  
Michael C Jennings

Previous studies have determined that neutral palladium(II) dibromide complexes template the formation of [2]pseudorotaxanes, albeit with weaker affinities than the analogous palladium(II) dichloride species. Here, the self-assembly of both [2]rotaxane (2) and [2]catenane (5) were attempted using a PdBr2L2 centre as the template, resulting in the desired interlocked structures. The structures were confirmed by NMR spectroscopy, CSI-MS, and single crystal X-ray diffraction analyses. [2]Rotaxane 2 was isolated in 53% and [2]catenane 5 in 41% yields. The lower yields observed in comparison to the chloride analogues can be attributed to the reduced template effect of the palladium(II) dibromide subunits, caused by both the poor steric fit of the bromides in the isophthalamide cleft and bromide’s reduced capacity as a hydrogen bond acceptor.Key words: rotaxane, catenane, hydrogen bonding, interlocked, supramolecular chemistry.


Molbank ◽  
10.3390/m1110 ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. M1110 ◽  
Author(s):  
Rebeca González-Fernández ◽  
Javier Borge ◽  
Pascale Crochet ◽  
Victorio Cadierno

The synthesis of a series of arene-osmium(II) complexes containing phosphinite-type ligands, namely, [OsCl2(η6-p-cymene){R2PO(CH2)nPh}] (R = Ph, n = 1 (4a), 2 (4b), 3 (4c); R = iPr, n = 1 (5a), 2 (5b), 3 (5c)) and [OsCl2(η6-benzene){iPr2PO(CH2)2Ph}] (7), is presented. All these compounds were characterized by elemental analysis and multinuclear NMR spectroscopy (31P{1H}, 1H and 13C{1H}), and the structure of [OsCl2(η6-p-cymene){Ph2PO(CH2)3Ph}] (4c) unequivocally confirmed through a single-crystal X-ray diffraction study. Attempts to generate the tethered species [OsCl2{η6:κ1(P)-C6H5(CH2)nOPR2}] by intramolecular exchange of the coordinated arene in 4-5a-c or 7, upon thermal or MW heating, failed.


1993 ◽  
Vol 48 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Lin Yang ◽  
Peter G. Jones ◽  
Reinhard Schmutzler

The reaction of 8 -trimethylsiloxyquinoline, 2 with PCl3, PhPCl2, and PhPF2 has furnished the corresponding 8 -quinolyl halophosphite derivatives, 3-5 . The synthesis of two metal complexes, 8 and 9, of 4 with Au(I) and Pt(II) is described. The new compounds were characterized by elemental analysis and by 1H and 31P NMR spectroscopy. A single crystal X-ray diffraction study of 4 has been conducted; a short intramolecular P ··· N contact (230.9 pm) and a long P-Cl bond (218.7 pm) were observed.


1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.


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